Safety requirements for automotive electronics are being standardized in a number of application segments. An example are chassis applications which United States government legislation requires to be standardized for each new vehicle from 2012. A further example is electric power steering.
Automotive braking applications and steering applications also both require sophisticated electronic solutions that allow switching to a safe state in case a malfunction is detected. Accordingly, awareness of safety issues, for example by a system-on-chip (SoC), is of increasing importance in today's vehicular applications, although the usage of such devices is not limited to such applications. However, the safety level required differs from application to application. For example, some applications may require Safety Integrity Level (SIL) 3, whilst other applications may require SIL 2. Safety Integrity Levels are defined as a relative level of risk-reduction provided by a safety function, or as a specific target level for risk reduction. Four SIL levels are defined by the International Standard IEC 61508, ranging from SIL 4, being the most dependable, to SIL 1, being the least dependable.
Different levels of safety may require varying amounts of redundancy of building blocks and connectivity within the SoC. As a result of this, known SoCs are designed with a specific SIL in mind. Thus, for applications requiring different levels of safety, different SoCs must be developed. Since redundancy of the building blocks is usually tightly coupled to the architecture of the SoC, this is an issue for creating a family of safety aware devices.
However, the need to develop multiple SoC architectures to support multiple SILs makes the development of safety aware devices complex and costly.